The present invention relates to a system for connecting together a first tube and a second tube, the system comprising a clamping collar suitable for being tightened around the abutted ends of the two tubes, and a washer secured to the clamping collar by securing means.
A clamping system of this type is known from European patent EP 1 451 498. In that patent, the facing tube ends present bearing surfaces that project relative to the cylindrical outside surfaces of said tubes. The clamping collar comprises a clamping band of section that may for example be substantially V-shaped or U-shaped, so that the branches formed by that section bear respectively against the bearing surface of the first tube and against the bearing surface of the second tube. Thus, tightening the collar tends to hold the two tubes clamped one against the other. The V-shaped section is advantageous insofar as it serves, while the collar is being tightened, to move the tubes towards each other.
For example, the means for tightening the band may comprise a nut-and-bolt system. Thus, the ends of the band may be upstanding so as to form bearing tabs each having a hole through which a bolt can be inserted. A nut is arranged behind one of the tabs so that turning the bolt tightens the collar. Nevertheless, other tightening means may be provided, e.g. of the type operating by hooking, in particular of the type comprising a hook stood up relative to the band and a lug likewise stood up relative to the band, the hook becoming attached behind the lug so as to hold the collar in the tightened state.
The washer of the clamping system may in particular serve to provide sealing for the connection between the two tubes, by presenting for this purpose a sealing portion that, when the system is tightened on the tubes, is engaged between two sealing surfaces belonging respectively to the first tube and to the second tube.
In certain applications, it is also desired to guarantee that the clamping system occupies a certain angular position relative to the first tube, in particular for controlling the position of the bearing tabs and of the bolt and to optimize the space occupied by the system, or indeed to facilitate access for operators to the clamping system while it is being assembled or disassembled.
International application WO 2016/034820 discloses another clamping system for connecting two tubes together, the system comprising a clamping collar having a retaining tab. The retaining tab presents a fastener portion on the clamping band of the collar and an attachment portion whereby said retaining tab is suitable for being attached to the first tube. Such a retaining tab provides satisfaction for holding the angular position of the clamping collar relative to the first tube. Nevertheless, it occupies additional space outside the first tube and needs to be attached to the first tube during an additional step, e.g. a welding step, thereby lengthening the process of assembling the tubes together.
There therefore exists a need for a novel type of connection and clamping system for remedying the above-mentioned drawbacks, and in particular for controlling the angular position of the clamping system relative to the first tube in a manner that is simple, fast, and compact.